A man and child view a display of a great white shark on the Manhattan Beach Pier July 6, one day after a swimmer was bitten by a great white shark off the Southern California beach city.(Photo: John Antczak, AP)

In the United States, there were 106 confirmed, unprovoked great white shark attacks, including 13 fatalities, from 1916 to 2011, according to the Florida Museum of Natural History's Shark Attack File. Of those, 78 attacks and eight fatalities were in California, according to the shark file.

Attacks by great whites represent a small proportion of overall shark attacks, said George Burgess, director of the Florida Program for Shark Research. For example, in 2013, there were 47 shark attacks in the USA, according to the shark file. On average, there is only about one great white attack per year.

In the attack last weekend at Manhattan Beach in Southern California, the juvenile shark was caught on a fishing line when long-distance swimmers happened to be passing by.

Juvenile sharks in particular will feed closer to shore because they tend to go after stingrays, fish and smaller animals that are more abundant and easier to catch, says Chris Lowe, a marine biology professor at California State University at Long Beach.

Typically, sharks will simply "mind their own business," Lowe said.

A visitor to the pier in Manhattan Beach, Calif., poses with a model of a great white shark outside an aquarium on Sunday, July 6, 2014, the day after a juvenile white shark hooked by a fisherman bit a swimmer.(Photo: John Antzak, AP)

A growing shark population

One reason for the growing numbers is conservation efforts that began in the 1990s, Curtis says..

The exact number of great whites overall is unknown. Estimates put the number of great white sharks along the California coast at more than 2,000, according to a June study by Lowe and others.

Great whites are a vulnerable population because they don't produce a lot of young, and used to be hunted for their jaws and their fins, as well as victim of by-catch by fisheries, according to a NOAA statement.

"It's a success story for fisheries management," Curtis said.

Under federal law, great whites are considered a prohibited species. In federal waters, which is generally 3 miles or more from shore, great whites cannot be hunted and, if inadvertently caught, must be released with a "minimum of injury," according to NOAA.

In California, the state's Department of Fish and Wildlife regulates waters closer to shore and prohibits hunting, pursuing, catching, capturing or killing great white sharks.

In Southern California, great white sightings have occurred "almost on a daily basis" starting last year, said Scott Miller, spokesman for the Los Angeles County Fire Department, which oversees the lifeguard division.

When someone sees a shark, lifeguards put out signs along the beach notifying people of a sighting, and sometimes guards even get on jet skis to "trail" the sharks so they will swim away from shore, Curtis said.

So far, beach closures have not been part of the process to warn people, Miller said.

'A perfect storm'

Steve Robles, Saturday's shark bite victim, said he was aware of the great white sightings, but didn't think they posed a threat.

Robles said he thinks the shark was agitated and would not have normally bitten a swimmer.